Automatic drain valve for air tanks



April 10, 1951 J. M. PARKS 2,548,236

' AUTOMATIC DRAIN VALVE FOR AIR TANKS Filed Feb. 3, 1948 Fig.

Fig. 3

Fig. 4

James M. Parks INVENTOR.

Patented Apr. 10, 1951 UNITED STATES PATENT OFFICE 1 Claim.

This invention relats to an automatic drain or bleeder valve assembly which may readily and easily be attached to any compressed air tank.

It is well known to those skilled in the art that withdrawal of air from a compressed air tank for use in various tools, such as a spray tool, a

paint gun, air brakes, or other similar tools, is

attached with certain difiiculties. Very often the water condensate in the air supply tank, passes through the air supply line, gets into the tool and causes unnecessary clogging of the tool. Periodically, the tool must be dismantled and cleaned out before re-use. Also, some means must be provided for withdrawing unnecessarily large amount of condensate from the air supply tank periodically. It is, therefore, a primary object of the instant invention to prevent condensate from getting into an air supply line by automatically removing the condensate from the air supply tank.

It is a further object to supply valve means whereby water condensate can be withdrawn automatically from the air supply tank and discharged through the valve particularly at such time as the air tool is being employed.

Another object of the invention is to provide means for keeping an air tank substantially dry at all times. Knowing that the air tank is substantially dry, the operator may have no fear of withdrawing air for use in spraying paints or operating hammers or other like tools where the presence of a condensate in the tool will cause substantial harm.

- These, together with various ancillary objects and features of the invention which will later become apparent as the following description proceeds, are attained by the device, a preferred embodiment of which has been illustrated by way of example only in the accompanying drawings, wherein:

Figure l is an elevational View, partly diagrammatic, showing the manner of connecting the drain valve to an air tank;

Figure 2 is a horizontal sectional view taken substantially on the plane of section line 2-2 of Figure 3;

Figure 3 is a vertical section through the valve showing some parts in elevation;

Figure 4 is an isometric view of the valve assembled with parts thereon.

Specific reference is now made to the drawings. In the several views in the accompanying drawings and in the following specification, reference characters indicate corresponding elements throughout.

Generally indicated at ID is the main housing of the drain valve which consists of compartments [2 and I4 separated by and threadedly connected to a middle compartment [6 having a plurality of radial bores l8 at the periphery of which bores will be found ports t9 leading to the atmosphere.

At the top of, the valve drain housing I0 is a threaded hose connection 20 between the drain valve and the air supply tank. Element 22 is a nut to secure this hose connection to the drain valve and element 24 is a vertical bore or orifice in said hose connection.

At the bottom of the drain valve housing is a similar threaded hose connection 26 with vertical bore or orifice 28 which connection is attachable to an air line as shown in Figure 1.

Vertically disposed in the center of the drain valve is valve stem 30 at the top of which is secured an inlet valve 32 communicative with orifice 24. A second valve 34 secured to the valve stem is so positioned on the valvestem as to be communicative with a vertical conduit 36 axially disposed through the middle compartment l6 having a plurality of circumferential apertures 35 communicative with the radial bores l8.

It will be noted, therefore, that valves 32 and 34 will be found to move in compartment 36.

Through the middle compartment It a grooved nut 40 secured on the valve stem and movable in the vertical conduit 36 is provided. Generally indicated at 42 is suitable packing placed in groove 43 to provide an air-tight seal with the inner walls of vertical conduit 36. The grooved nut serves as a sealer ring or gasket to keep Water and slush from entering piston chamber 38.

Wound around the valve stem is a spring 44, one terminus of which encircles the grooved nut 40, and abuts the bottom inner surface of the middle section as at 4| and the other terminus abuts a washer 46.

Generally indicated at 48 is a metal washer. Numeral 50 is a sealing gasket in the form of a rubber cup and 52 is a gasket spreader. A conventional retaining nut is provided at 54. Elements 48, 5!], and 52 together make up the pressure responsive member or piston. The washer 48 is employed to keep the rubber cup 50 from folding back when air comes in through vertical bore 28.

The manner of attaching or assembling the drain valve to the air supply tank is shown at Figure 1 wherein: numeral 66 is the tank, numeral 68 is an outlet air line to which is connected a conventional air valve 70. A by-pass air line 12 is connected to the bottom of the drain valve 56.

The automatic drain valve of the instant invention operates in the following manner. When air is being withdrawn from the air supply tank and used with an air tool, air from a by-pass line of said tool is caused 'to enter the bottom of the drain valve where the air pressure impinges on the pressure sensitive member. As a consequence, this member moves upwardly against the spring which, in turn, moves the valve stem in the same upward direction, pushing valve 32 into the vertical bore 24 and closing it at this point. The second valve 34 also moves up and opens vertical conduit 36. Water which has previously collected in compartment 35 is, therefore, caused to drain through the radial bores 18 and out through the ports l9. Thus it will be seen that when the operator is actually using an air tool the automatic drain valve will be draining water collected in the valve. When the operator shuts ofi the air tool the spring pressure 43, one end resting on washer 45 the other end resting on the middle section of main body as at M, will cause the valve stem to move downwardly whereby valve 34 closes the vertical conduit 3% and valve 32 opens the vertical bore 24. In this phase of operation, water will not be drained through the port, but condensate water of the air supply tank 66 will be caused to flow through the vertical bore 24 and collect in the upper compartment 36.

Thus a simple and efilcient means is provided automatically for continuously draining condensate from a tank into a valve when air is not being withdrawn from the tank and automatically discharging the collected condensate from the valve when air is being withdrawn from the tank and used in an air tool.

The drain valve may be constructed of suitable, durable material.

In view of the foregoing description taken in conjunction with the accompanying drawings, it is believed that a clear understanding of the device will be quite apparent to those skilled in this art. A more detailed description is accordingly deemed unnecessary.

It is to be understood, however, that even though there is herein shown and described a preferred embodiment of the invention the same is susceptible to certain changes fully comprehended by the spirit of the invention as herein described and the scope of the appended claim.

Having described the invention, what is claimed as new is:

An automatic valve comprising a housing: said housing being formed from three compartments, the upper compartment being of cup-shaped form having a threaded aperture centrally disposed in its base and a threaded month, said upper compartment being in inverted relation to the lower compartment, said lower compartment being of a form similar to said upper compartment, the middle compartment being of discshape having longitudinally extending peripheral flanges, each of said flanges being externally threaded and receivable in said threaded mouth of said upper compartment and lower compartment, an outlet threadably mounted at the top of the upper compartment in said aperture communicative with an air supply tank, an inlet threadably mounted at the bottom of the lower compartment communicative with an air line, a longitudinal bore in said middle compartment and a plurality of radial bores in the middle compartment containing ports leading to the atmosphere and communicative with said longitudinal bore, valve stem centrally disposed in said longitudinal bore and in the housing, an inlet valve secured to the top of said valve stem and cooperable with said outlet, an outlet valve secured to said valve stem above and cooperable with said radial bores, means for actuating said valve stems whereby the valves are simultaneously and alternately operable, the means for actuating the valve stem consisting of a pressure responsive member movable against the terminus of a spring means whose other terminus abuts the bottom inner surface of the middle compartment, and a grooved nut secured to said valve stem freely movable in said vertical bore and containing appropriate packing in the groove to obtain an air tight fitting.

JAMES M. PARKS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,579,073 Bullock Mar. 30, 1926 2,328,649 Jerome Sept. '7, 1943 

